Method for making 1,1,3,3-tetrachloropropene

ABSTRACT

A process for the manufacture of 1,1,3,3-tetrachloropropene, the process comprising dehydrochlorinating 1,1,1,3,3-pentachloropropane.

This application is a continuation application of U.S. Non-Provisionalapplication Ser. No. 15/311,570 filed on Nov. 16, 2016, which is a U.S.National-Stage Application of PCT/US2015/030800 filed on May 14, 2015,and claims the benefit of U.S. Provisional Patent Application Ser. No.61/994,323 filed on May 16, 2014, which are incorporated herein byreference.

FIELD OF THE INVENTION

Embodiments of the present invention relate to methods for manufacturing1,1,3,3-tetrachloropropene from 1,1,1,3,3-pentachloropropane.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 6,313,360 teaches a process for the manufacture of1,1,1,3,3-pentachloropropane by reacting carbon tetrachloride and vinylchloride in the presence of a catalyst mixture comprisingorganophosphate solvent, iron metal, and ferric chloride underconditions sufficient to produce the 1,1,1,3,3-pentachloropropane. Theresultant 1,1,1,3,3-pentachloropropane is contained within a productmixture that is first separated within, for example, a flash tower toremove ferric chloride, organophosphates, and other high boilingcomponents. This flash tower can be operated at temperatures below 116°C. and from about 0.02 to 0.07 atmospheres. The distillate fraction isthen further purified using two or more distillation towers that may beoperated under partial vacuum at temperatures preferably less than 138°C. The production of 1,1,1,3,3-pentachloropropane is likewise disclosedin U.S. Pat. No. 6,187,978.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart diagram of a process for producing1,1,3,3-tetrachloropropene according to embodiments of the inventionwherein a purified stream of 1,1,1,3,3-pentachloropropane is reactivelydistilled.

FIG. 2 is a flow chart diagram of a process for producing1,1,3,3-tetrachloropropene according to embodiments of the inventionwherein a partially purified stream of 1,1,1,3,3-pentachloropropane isreactively distilled.

FIG. 3 is a flow chart diagram of a process for producing1,1,3,3-tetrachloropropene according to embodiments of the inventionwhere a crude stream of 1,1,1,3,3-pentachloropropane is reactivelydistilled.

FIG. 4 is a graph showing certain results from Examples 1 and 2.

FIG. 5 is a graph showing certain results from Example 3.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a process for themanufacture of 1,1,3,3-tetrachloropropene, the process comprisingdehydro chlorinating 1,1,1,3,3-pentachloropropane.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Embodiments of the invention are based, at least in part, on thediscovery of a process for producing 1,1,3,3-tetrachloropropene(HCC-1230za) by dehydrochlorinating 1,1,1,3,3-pentachloropropane(HCC-240fa) in the presence of a Lewis acid and optionally an oxidizingagent. In one or more embodiments, the 1,1,3,3-tetrachloropropene iscontinuously produced and removed from the dehydrochlorination vessel,along with one or more byproducts, by employing reactive distillationtechniques. In certain advantageous embodiments, the1,1,1,3,3-pentachloropropane is contained within a crude1,1,1,3,3-pentachloropropane stream that may include carbontetrachloride.

Process for Producing 1,1,1,3,3-Pentachloropropane

In one or more embodiments, 1,1,1,3,3-pentachloropropane may be producedby the use of known methods. In this regard, U.S. Pat. Nos. 6,313,360and 6,187,978 are incorporated herein by reference. In one or moreembodiments, the 1,1,1,3,3-pentachloropropane is produced by reactingcarbon tetrachloride and vinyl chloride in the presence of a catalystmixture comprising organophosphate solvent (e.g., tributylphosphate),iron metal, and ferric chloride under conditions sufficient to produce1,1,1,3,3-pentachloropropane.

Isolation of 1,1,1,3,3-Pentachloropropane Stream from Raw Product Stream

In one or more embodiments, a raw 1,1,1,3,3-pentachloropropane stream,which is produced by the reaction defined above, may be purified orpartially purified by employing known techniques, such as thosedisclosed in U.S. Pat. No. 6,313,360, which is incorporated herein byreference. In one or more embodiments, a raw1,1,1,3,3-pentachloropropane stream is prepared by reacting carbontetrachloride with vinyl chloride in the presence of organophosphatesolvent, iron metal, and/or ferric chloride as described above. This raw1,1,1,3,3-pentachloropropane stream may then undergo a first separationwherein ferric chloride, amines, nitriles, amides, and/or phosphates, aswell as other high boiling components, are separated from a distillatefraction that may include carbon tetrachloride, vinyl chloride, and1,1,1,3,3-pentachloropropane, as well as other light byproducts such asvarious chlorinated compounds such as chloroform and chlorobutane. Inone or more embodiments, this first separation step produces a crude1,1,1,3,3-pentachloropropane stream, which will be described in greaterdetail below.

In one or more embodiments, this first separation step may take place ata temperature from about 70° C. to about 120° C., or in otherembodiments from about 80° C. to about 90° C.

In one or more embodiments, this first separation step may take place ata pressure of at least 0.020 atmospheres, in other embodiments at least0.025 atmospheres, and in other embodiments at least 0.030 atmospheres.In these or other embodiments, this first separation step may take placeat pressures of at most 0.07 atmospheres, in other embodiments at most0.05 atmospheres, and in other embodiments at most 0.04 atmospheres. Inparticular embodiments, this first separation step may take place atpressures from about 0.02 atmospheres to about 0.07 atmospheres, or inother embodiments from about 0.025 atmospheres to about 0.040atmospheres.

Where further purification of the 1,1,1,3,3-pentachloropropane stream isdesired, a second separation step may be performed. According to thissecond separation step, the distillate fraction from the firstseparation step (i.e., the 1,1,1,3,3-pentachloropropane stream), whichmay contain unconverted vinyl chloride, unconverted carbontetrachloride, and other light byproducts, is further separated toisolate the 1,1,1,3,3-pentachloropropane and its isomers. In one or moreembodiments, the second purification step includes a second distillationto produce a partially purified 1,1,1,3,3-pentachloropropane stream.

In one or more embodiments, this second separation step may take placeat a temperature of from about 60° C. to about 160° C., or in otherembodiments from about 70° C. to about 130° C.

In one or more embodiments, this second separation step may take placeat a pressure of at least 0.05 atmospheres, in other embodiments atleast 0.10 atmospheres, and in other embodiments at least 0.20atmospheres. In these or other embodiments, this first separation stepmay take place at pressures of at most 0.50 atmospheres, in otherembodiments at most 0.40 atmospheres, and in other embodiments at most0.30 atmospheres. In particular embodiments, this first separation stepmay take place at pressures from about 0.05 atmospheres to about 0.50atmospheres, or in other embodiments from about 0.10 atmospheres toabout 0.30 atmospheres.

Characteristics of 1,1,1,3,3-Pentachloropropane Stream

The 1,1,1,3,3-pentachloropropane used in the process of this inventionmay be prepared as described above. In one or more embodiments, the1,1,1,3,3-pentachloropropane is contained within a1,1,1,3,3-pentachloropropane stream, which includes the1,1,1,3,3-pentachloropropane and one or more optional constituents.

In one or more embodiments, the 1,1,1,3,3-pentachloropropane stream is apurified 1,1,1,3,3-pentachloropropane stream that is at leastsubstantially devoid of other chemical constituents. As used herein,substantially devoid refers to that amount or less of other chemicalconstituents that would otherwise have a deleterious impact on thepractice of one or more aspects of the invention. In one or moreembodiments, the purified 1,1,1,3,3-pentachloropropane stream issubstantially devoid of carbon tetrachloride, vinyl chloride,chlorobutane, chloroform, pentachloropropane isomers other than1,1,1,3,3-pentachloropropane (e.g. 1,1,1,2,3-pentachloropropane), ironand/or iron compounds, amines, nitriles, amides, and phosphates. In oneor more embodiments, the purified 1,1,1,3,3-pentachloropropane streamincludes less than 5,000 ppm (i.e. 0.5 wt %), in other embodiments lessthan 1000 ppm, and in other embodiments less than 500 ppm1,1,1,2,3-pentachloropropane based on the entire weight of the stream.In one or more embodiments, the purified 1,1,1,3,3-pentachloropropanesteam includes less than 10,000 ppm (i.e. 1 wt %), in other embodimentsless than 500 ppm, and in other embodiments less than 100 ppm carbontetrachloride based upon the entire weight of the stream. In these orother embodiments, the partially purified 1,1,1,3,3-pentachloropropanesteam includes less than 100 ppm, in other embodiments less than 10 ppm,and in other embodiments less than 5 ppm iron and/or iron compounds,amines, nitriles, amides, and phosphates.

In other embodiments, the 1,1,1,3,3-pentachloropropane stream employedin the practice of this invention is a partially purified1,1,1,3,3-pentachloropropane stream, which refers to a stream that issubstantially devoid of compounds other than pentachloropropanes. In oneor more embodiments, the partially purified steam may include at most2.0 wt % pentachloropropanes other than 1,1,1,3,3-pentachloropropane(i.e. other pentachloropropane isomers) including, but not limited to,1,1,1,2,3-pentachloropropane. In one or more embodiments, the partiallypurified 1,1,1,3,3-pentachloropropane steam is substantially devoid ofcarbon tetrachloride, vinyl chloride, iron and/or iron compounds,amines, nitriles, amides, and phosphates. In particular embodiments, thepartially purified 1,1,1,3,3-pentachloropropane steam includes less than10,000 ppm (i.e. 1 wt %), in other embodiments less than 500 ppm, and inother embodiments less than 100 ppm carbon tetrachloride. In these orother embodiments, the partially purified 1,1,1,3,3-pentachloropropanesteam includes less than 100 ppm, in other embodiments less than 10 ppm,and in other embodiments less than 5 ppm iron and/or iron compounds,amines, nitriles, amides, and phosphates.

In yet other embodiments, the 1,1,1,3,3-pentachloropropane stream is acrude 1,1,1,3,3-pentachloropropane stream that is delivered directlyfrom one or more of the processes described above for the synthesis of1,1,1,3,3-pentachloropropane. In one or more embodiments, the crude1,1,1,3,3-pentachloropropane steam is substantially devoid of ironand/or iron compounds, amines, nitriles, amides, and phosphates. In oneor more embodiments, the crude 1,1,1,3,3-pentachloropropane steamincludes less than 100 ppm, in other embodiments less than 10 ppm, andin other embodiments less than 5 ppm iron and/or iron compounds, amines,nitriles, amides, and phosphates. In one or more embodiments, the crude1,1,1,3,3-pentachloropropane steam includes carbon tetrachloride. In oneor more embodiments, the crude 1,1,1,3,3-pentachloropropane steamincludes from about 10 wt % to about 70 wt %, in other embodiments fromabout 20 wt % to about 60 wt %, and in other embodiments from about 30wt % to about 50 wt % carbon tetrachloride based upon the entire weightof the stream. In one or more embodiments, the crude1,1,1,3,3-pentachloropropane stream includes one or more chlorinatedcompounds selected from vinyl chloride, chlorobutane, and chloroform. Inone or more embodiments, the crude 1,1,1,3,3-pentachloropropane steamincludes from about 0.1 wt % to about 10 wt %, in other embodiments upto about 6 wt %, and in other embodiments up to about 5 wt % of one ormore chlorinated compounds selected from vinyl chloride, chlorobutane,chloroform, and combinations thereof, based upon the entire weight ofthe stream.

Process for Producing 1,1,3,3-Tetrachloropropene

As indicated above, 1,1,3,3-tetrachloropropene may be formed bydehydrochlorinating 1,1,1,3,3-pentachloropropane in the presence of aLewis acid and optionally an oxidizing agent. Exemplary Lewis acidsinclude halides of metals and semimetals, such as aluminum, titanium,tin, antimony, and iron halides. In particular embodiments, ferricchloride is employed as the Lewis acid. The Lewis acid can be addedeither dry or as a slurry. Exemplary oxidizing agents include variouschlorides including chlorine and sulfuryl chloride. In particularembodiments, chlorine is used as the oxidizing agent. For ease ofdescription, specific embodiments of this invention may be describedwith respect to ferric chloride and chlorine, and the skilled artisanwill be able to readily extend practice of these embodiments to otherLewis acids and oxidizing agents. Hydrogen chloride may be produced as abyproduct. The ferric chloride may be introduced to the1,1,1,3,3-pentachloropropane stream prior to or during thedehydrochlorination reaction.

Where the dehydrochlorination reaction is conducted within a reactionvessel, the ferric chloride may be separately and individually added tothe reaction vessel continuously during the course of the reaction orperiodically during the course of the reaction. For example, ferricchloride may be fed into the reaction vessel once per 0.5 to 3 liquidturnovers, wherein one turnover is the time calculated as the ratio ofliquid inventory in the reaction vessel to the liquid flow rate out ofthe reaction vessel.

In one or more embodiments, the amount of ferric chloride present duringthe dehydrochlorination reaction is a catalytic amount, which refers tothat amount that promotes dehydrochlorination reaction. In one or moreembodiments, the amount of ferric chloride present during thedehydrochlorination reaction may be at least 30 ppm, in otherembodiments at least 100 ppm, and in other embodiments at least 200 ppm,based upon the weight of the reaction mixture, which includes allconstituents within the bottom of the distillation column. In these orother embodiments, the amount of ferric chloride present during thedehydrochlorination reaction may be at most 10,000 ppm, in otherembodiments at most 5000 ppm, and in other embodiments at most 3000 ppm,based upon the weight of the reaction mixture. In one or moreembodiments, the amount of ferric chloride present during thedehydrochlorination reaction is from about 30 to about 10,000 ppm, inother embodiments from about 100 to about 5000 ppm, and in otherembodiments from about 200 to about 3000 ppm, based upon the weight ofthe reaction mixture.

In one or more embodiments, where an oxidizing agent, such as chlorine,is present during the dehydrochlorination reaction, the amount ofoxidizing agent may be from about 100 ppm to about 3 wt %, or in otherembodiments from about 1,000 ppm to about 10,000 ppm.

A process for the preparation of 1,1,3,3-tetrachloropropene may includereactive distillation, which includes dehydrochlorinating1,1,1,3,3-pentachloropropane in a reaction zone in the presence offerric chloride to produce 1,1,3,3-tetrachloropropene and hydrogenchloride while removing the 1,1,3,3-tetrachloropropene and hydrogenchloride from the reaction zone by distillation during the course of thereaction. In one or more embodiments, the 1,1,3,3-tetrachloropropene andhydrogen chloride are removed continuously during the course of thereaction. In one or more embodiments, the 1,1,1,3,3-pentachloropropaneis fed continuously into the reactive distillation system. The reactivedistillation system may be operated in a continuous process wherein the1,1,1,3,3-pentachloropropane stream addition and the1,1,3,3-tetrachloropropene product removal, as well as the removal ofhydrogen chloride byproduct, are performed at the same time.

In one or more embodiments, the reactive distillation system may includea reaction zone, a separation zone, and a condensing zone. The1,1,1,3,3-pentachloropropane stream enters the reaction zone, which isgenerally located below the separation zone. The liquid in the reactionzone is heated and agitated. Practice of the present invention is notlimited by the process or mechanism for providing agitation and heat.For example, the agitation can be provided via pumped circulation loopsor by stirring. Heat can be provided through a jacket on the vessel, orby internal heat exchangers, or by external heat exchangers.

In one or more embodiments, the 1,1,1,3,3-pentachloropropane stream doesnot contain more than 1,000 ppm water.

In one or more embodiments, the reactive distillation step may takeplace at temperatures greater than 20° C., in other embodiments greaterthan 30° C., in other embodiments greater than 40° C., and in otherembodiments greater than 50° C. In one or more embodiments, reactivedistillation may take place at a temperature of from about 60° C. toabout 160° C., or in other embodiments from about 80° C. to about 100°C.

In one or more embodiments, the reactive distillation step may takeplace at pressures of at least 0.05 atmospheres, in other embodiments atleast 0.10 atmospheres, and in other embodiments at least 0.20atmospheres. In these or other embodiments, this first separation stepmay take place at pressures of at most 0.50 atmospheres, in otherembodiments at most 0.40 atmospheres, and in other embodiments at most0.30 atmospheres. In particular embodiments, this first separation stepmay take place at pressures from about 0.05 atmospheres to about 0.50atmospheres, or in other embodiments from about 0.10 atmospheres toabout 0.40 atmospheres.

Process for Producing 1,1,3,3-Tetrachloropropene Using ReactiveDistillation

An exemplary process for preparing 1,1,3,3-tetrachloropropene from apurified 1,1,1,3,3-pentachloropropane stream is shown in FIG. 1. Theprocess includes providing a purified 1,1,1,3,3-pentachloropropanestream 12 and a ferric chloride source 14, and delivering the same to areactive distillation column 20, wherein 1,1,1,3,3-pentachloropropane isdistilled under appropriate heat and pressure to form a condensatefraction 22, which may include both 1,1,3,3-tetrachloropropene andhydrogen chloride, as well as other volatile byproducts.

The reactive distillation step selectively dehydrochlorinates1,1,1,3,3-pentachloropropane to make hydrogen chloride (HCl) and1,1,3,3-tetrachloropropene, where 1,1,3,3-tetrachloropropene andhydrogen chloride are distilled overhead. As suggested above, thisreactive distillation may take place at temperatures from about 60° C.to about 160° C. and pressures from about 0.05 atmospheres to about 0.5atmospheres. As also suggested above, ferric chloride 14 can be added tothe purified 1,1,1,3,3-pentachloropropane stream 12 before purified1,1,1,3,3-pentachloropropane stream 12 is introduced to reactivedistillation column 20. In other embodiments, ferric chloride 14 can beintroduced to purified 1,1,1,3,3-pentachloropropane stream 12 withinreactive distillation column 20.

In one or more embodiments, an oxidizing agent 15, such as chlorine, isintroduced to reactive distillation column 20. This oxidizing agent 15may be introduced to the feed line introducing1,1,1,3,3-pentachloropropane stream 12, or a feed line 17 that directlyintroduces oxidizing agent 15 to reactive distillation column 20.

A volatiles fraction 24, which primarily includes hydrogen chloride, maybe collected from distillation column 20 and vented.

The bottom fraction 26 from reactive distillation column 20 can berouted to heavy ends purge 28.

Condensate fraction 22, which may also be referred to as sour1,1,3,3-tetrachloropropene fraction 22 or condensation fraction 22, isrich in 1,1,3,3-tetrachloropropene, and contains hydrogen chloride.Condensate fraction 22 may be further purified by removal of hydrogenchloride within a hydrogen chloride separator 30. In one or moreembodiments, hydrogen chloride separator 30 may include a strippingtower. In other embodiments, separator 30 may include a distillationcolumn.

Volatiles fraction 32, which primarily includes hydrogen chloride, maybe vented from separator 30 or recovered overhead. Other light compoundswhich have a boiling point below that of the desired1,1,3,3-tetrachloropropene, may be collected as a distillate fraction34, which may be drawn by a top section side draw at or near the topsection of a distillation tower used as hydrogen chloride separator 30.Distillate fraction 34 may also be referred to as light ends draw 34.

In one or more embodiments, a stripping gas 36 may be introduced intoseparator 30 where separator 30 is a stripping tower.

The desired 1,1,3,3-tetrachloropropene product 38 may be recovered via abottom section or a lower side draw 40 of a distillation tower, where adistillation tower is used as separator 30. Where separator 30 is adistillation tower, the distillation may take place at temperatures fromabout 60° C., to about 160° C., and pressures from about 0.03atmospheres to about 1.1 atmospheres.

In one or more embodiments, desired 1,1,3,3-tetrachloropropene product38 can be further purified by using, for example, additionaldistillation techniques to provide a product of desired purity.

Process for Producing 1,1,3,3-Tetrachloropropene Using PartiallyPurified Stream

An exemplary process for producing 1,1,3,3-tetrachloropropene from apartially purified 1,1,1,3,3-pentachloropropane stream is show in FIG.2. To begin with, 1,1,1,3,3-pentachloropropane is prepared within areaction vessel 50 by combining vinyl chloride 52, carbon tetrachloride54, iron powder 56, and an organophosphate (e.g., tributylphosphate) 58.As is generally known in the art, the reaction taking place within areactor 50, which may be referred to as the Kharasch reaction, takesplace at temperatures of from about 80° C. to about 125° C. The Kharaschreaction combines vinyl chloride and carbon tetrachloride (CTC) to make1,1,1,3,3-pentachloropropane. As is also known in the art, where excesscarbon tetrachloride is supplied to reactor 50, reaction selectivity canbe improved thereby producing fewer heavy ends.

The crude 1,1,1,3,3-pentachloropropane product stream 60 exits reactor50 and is delivered to a reflux evaporator 64, wherein the1,1,1,3,3-pentachloropropane and light ends are separated as an overheadfraction 66 from the other components, which can include heavy ends andcatalyst components. The other components, which have a higher boilingpoint and include, for example, organophosphates, are separated as aheavy ends fraction 68. In particular embodiments, heavy ends fraction68 can be routed to heavy ends purge 70 or, depending on the nature ofheavy ends 68, provided as a catalyst recycle stream 72 to reactor 50.In one or more embodiments, reflux evaporator 64 may be operated attemperatures of from about 70° C. to about 120° C., and pressures offrom about 0.02 atmospheres to about 0.07 atmospheres.

Overhead fraction 66, which may also be referred to as raw1,1,1,3,3-pentachloropropane product stream 66, crude1,1,1,3,3-pentachloropropane product stream 66, or distillate stream 66,contains unconverted carbon tetrachloride and may optionally be furtherpurified to remove carbon tetrachloride. This may include furtherdistillation at temperatures of from about 60° C. to about 160° C., andpressures of from about 0.07 atmospheres to about 0.5 atmospheres, torecover carbon tetrachloride and light ends in a light ends stream 82.For example, and as shown in FIG. 2, this partial purification step maytake place within a distillation column 80 to produce light ends stream82, which is rich in carbon tetrachloride, and a bottom ends fraction84, which is rich in 1,1,1,3,3-pentachloropropane. Light ends stream 82may also be referred to as overhead fraction 82. Light ends stream 82may be disposed of as a light ends purge 86. Since light ends stream 82contains unconverted carbon tetrachloride, it may be recycled back toreactor 50 as a recycle stream 88. When light ends stream 82 isrecycled, some light ends may also be purged from light ends purge 86 tocontrol accumulation of unwanted components.

Bottom fraction 84, which can be characterized as a partially purified1,1,1,3,3-pentachloropropane stream, may then be reactively distilledaccording to a process of the present invention. The reactivedistillation step selectively dehydrochlorinates1,1,1,3,3-pentachloropropane to make hydrogen chloride (HCl) and1,1,3,3-tetrachloropropene, where 1,1,3,3-tetrachloropropene andhydrogen chloride can be continuously distilled overhead. For example,partially purified 1,1,1,3,3-pentachloropropane stream 90 may beintroduced to reactive distillation column 92 together with ferricchloride 94. Ferric chloride 94 may also be referred to as Lewis acid94. As suggested above, ferric chloride 94 can be added either dry or asa slurry. As with the previous embodiments, ferric chloride 94 can beadded to partially purified 1,1,1,3,3-pentachloropropane stream 90before stream 90 is introduced to reactive distillation column 92. Inother embodiments, ferric chloride 94 can be introduced to partiallypurified 1,1,1,3,3-pentachloropropane stream 90 within reactivedistillation column 92. In one or more embodiments, ferric chloride 94may be introduced to partially purified 1,1,1,3,3-pentachloropropanestream 90 before stream 90 is introduced to reactive distillation column92 and directly to reactive distillation column 92. As with the previousembodiments, reactive distillation column 92 may be operated attemperatures from about 60° C. to about 160° C., and pressures of fromabout 0.05 atmospheres to about 0.5 atmospheres.

In one or more embodiments, an oxidizing agent 85, such as chlorine, isintroduced to reactive distillation column 92. This oxidizing agent 85may be introduced to the feed line introducing the1,1,1,3,3-pentachloropropane stream 84, or a feed line 87 that directlyintroduces oxidizing agent 85 to reactive distillation column 92.Oxidizing agent 85 may also be referred to as chlorine 85. In one ormore embodiments, oxidizing agent 85 may be introduced to the feed lineintroducing the 1,1,1,3,3-pentachloropropane stream 84 and to feed line87 that directly introduces oxidizing agent 85 to reactive distillationcolumn 92.

A volatiles fraction 96, which primarily includes hydrogen chloride, maybe collected from distillation column 92 and vented.

The bottom fraction 98 from reactive distillation column 92 can berouted to heavy ends purge 100.

Condensate fraction 102, which is rich in 1,1,3,3-tetrachloropropene,may be further purified by removal of hydrogen chloride within ahydrogen chloride separator 104. In one or more embodiments, hydrogenchloride separator 104 may include a stripping tower. In otherembodiments, separator 104 may include a distillation column.

Volatiles fraction 106, which primarily includes hydrogen chloride, maybe vented from separator 104. Other light compounds, which have aboiling point below that of the desired 1,1,3,3-tetrachloropropene, maybe collected as a distillate fraction, which may be drawn at or near thetop section of a distillation tower used as hydrogen chloride separator104.

The desired 1,1,3,3-tetrachloropropene product 110 may be recovered viaa bottom section or a lower side draw 110 of a distillation tower, wherea distillation tower is used as separator 104. Where separator 104 is adistillation tower, the distillation may take place at temperatures fromabout 60° C., to about 160° C., and pressures from about 0.03atmospheres to about 1.1 atmospheres.

In one or more embodiments, desired 1,1,3,3-tetrachloropropene product110 can be further purified by using, for example, additionaldistillation techniques to provide a product of desired purity. Forexample, distillation tower 112 may be employed. In one or moreembodiments, optional purification steps may be used to meet customerspecifications.

Process for Producing 1,1,3,3-Tetrachloropropene Using Crude Stream

An exemplary process for producing 1,1,3,3-tetrachloropropene from acrude 1,1,1,3,3-pentachloropropane stream is shown in FIG. 3. To beginwith, 1,1,1,3,3-pentachloropropane is prepared within a reaction vessel120 by combining vinyl chloride 122, carbon tetrachloride 124, ironpowder 126, and an organophosphate (e.g., tributylphosphate) 128. As isgenerally known in the art, the reaction taking place within a reactor120, which may be referred to as the Kharasch reaction, takes place attemperatures of from about 80° C. to about 125° C. As suggested above,the Kharasch reaction combines vinyl chloride and carbon tetrachloride(CTC) to make 1,1,1,3,3-pentachloropropane. As is also known in the art,where excess carbon tetrachloride is supplied to reactor 120, reactionselectivity can be improved thereby producing fewer heavy ends.

The raw 1,1,1,3,3-pentachloropropane product stream 130 exits reactor120 and is delivered to a refluxed evaporator 134, wherein the1,1,1,3,3-pentachloropropane and light ends are separated as an overheadfraction 136 from the other components, which can include heavy ends andcatalyst components. The other components, which have a higher boilingpoint and include, for example, organophosphates, are separated as aheavy ends fraction 138. In particular embodiments, heavy ends fraction138 can be routed to a heavy ends purge 140 or, depending on the natureof heavy ends 138, provided as a catalyst recycle stream 142 to reactor120. In one or more embodiments, reflux evaporator 134 may be operatedat temperatures of from about 70° C. to about 120° C., and pressures offrom about 0.02 atmospheres to about 0.07 atmospheres.

Overhead fraction 136, which may be referred to as crude1,1,1,3,3-pentachloropropane product stream 136, raw1,1,1,3,3-pentachloropropane product stream 136, or distillate stream136, exits evaporator 134 and is then reactively distilled according toa process of the present invention. The reactive distillation stepselectively dehydrochlorinates 1,1,1,3,3-pentachloropropane to makehydrogen chloride (HCl) and 1,1,3,3-tetrachloropropene, where1,1,3,3-tetrachloropropene and light ends can be continuously distilledoverhead. For example, crude 1,1,1,3,3-pentachloropropane stream 136 maybe introduced to reactive distillation column 152 together with ferricchloride 154. Ferric chloride 154 may also be referred to as Lewis acid154. As with the previous embodiments, ferric chloride 154 can be addedeither dry or as a slurry. As with the previous embodiments, ferricchloride 154 can be added to crude 1,1,1,3,3-pentachloropropane stream136 before stream 136 is introduced to reactive distillation column 152.In other embodiments, ferric chloride 154 can be introduced to crude1,1,1,3,3-pentachloropropane stream 136 within reactive distillationcolumn 152. In one or more embodiments, ferric chloride 154 may beintroduced to the feed line introducing the 1,1,1,3,3-pentachloropropanestream 136 before stream 136 is introduced to reactive distillationcolumn 152 and directly to reactive distillation column 152. As with theprevious embodiments, reactive distillation column 152 may be operatedat temperatures from about 60° C. to about 160° C., and pressures offrom about 0.05 atmospheres to about 0.5 atmospheres.

In one or more embodiments, an oxidizing agent 135, such as chlorine, isintroduced to reactive distillation column 152. Oxidizing agent 135 mayalso be referred to as chlorine 135. This oxidizing agent 135 may beintroduced to the feed line introducing the 1,1,1,3,3-pentachloropropanestream 136, or a feed line 137 that directly introduces oxidizing agent135 to reactive distillation column 152. In one or more embodiments,oxidizing agent 135 may be introduced to the feed line introducing the1,1,1,3,3-pentachloropropane stream 136 and directly to reactivedistillation column 152 by way of feed line 137.

A volatiles fraction 156, which primarily includes hydrogen chloride,may be collected from reactive distillation column 152 and vented.

The bottom fraction 158 from reactive distillation column 152 can berouted to heavy ends purge 160.

Condensate fraction 162, which is rich in 1,1,3,3-tetrachloropropene,may be further purified by removal of hydrogen chloride within ahydrogen chloride separator 164. In one or more embodiments, hydrogenchloride separator 164 may include a stripping tower. In otherembodiments, separator 164 may include a distillation column. Volatilesfraction 166, which primarily includes hydrogen chloride, may be ventedfrom separator 164. The other heavy components, including the desired1,1,3,3-tetrachloropropene, may be collected as stream 168.

The desired 1,1,3,3-tetrachloropropene product may be recovered via abottom section or a lower side draw 168 of a distillation tower, where adistillation tower is used as separator 164. Where separator 164 is adistillation tower, the distillation may take place at temperatures fromabout 60° C., to about 160° C., and pressures from about 0.03atmospheres to about 1.1 atmospheres.

Stream 168 may be further purified to separate the desired1,1,3,3-tetrachloropropene product 176 from a light ends stream 175containing other lightweight, lower boiling materials within stream 168.These lightweight materials may include, for example, unconverted carbontetrachloride, as well as other chlorinated compounds such as vinylchloride and the like. This separation may take place within adistillation column 172. Light ends stream 175 may also be referred toas overhead fraction 175. Light ends stream 175 may be disposed of as alight end purge 173. Since light ends stream 175 contains unconvertedcarbon tetrachloride, it may be recycled back to reactor 120 as arecycle. When light ends stream 175 is recycled, some light ends mayalso be purged from light ends purge 173 to control accumulation ofunwanted components.

The desired product 176 is removed as a heavy ends fraction 174. In oneor more embodiments, distillation tower 172 may be operated attemperatures from about 60° C., to about 160° C., and pressures fromabout 0.05 atmospheres to about 0.5 atmospheres.

In one or more embodiments, desired 1,1,3,3-tetrachloropropene product176 can be further purified by using, for example, additionaldistillation techniques to provide a product of desired purity. Forexample, a distillation tower 178 may be employed. In one or moreembodiments, optional purification steps may be used to meet customerspecifications.

In order to demonstrate the practice of the present invention, thefollowing examples have been prepared and tested. The examples shouldnot, however, be viewed as limiting the scope of the invention. Theclaims will serve to define the invention.

EXAMPLES

For the Tables below, as above, HCC-1230za is representative of1,1,3,3-tetrachloropropene and HCC-240fa is representative of1,1,1,3,3-pentachloropropane.

The reaction vessel for all examples was a 3-liter Pyrex™ (CorningIncorporated) glass round-bottom flask equipped with a graduatedaddition funnel and a 20-tray Oldershaw-type vacuum-jacketed Pyrex™glass distillation column. Atop the column was a reflux head andcondenser, with a side draw tube leading to a product receiver. Theentire system was connected to a controlled vacuum source. The exampleswere conducted in a generally semi-batch operation, with discreetweighed overhead samples collected and analyzed by gas chromatography.1,1,1,3,3-Pentachloropropane was introduced into the bottoms flaskperiodically via the addition funnel.

Example 1—No Chlorine Addition

In Example 1, the bottoms flask was charged with 0.26 grams anhydrousferric chloride (FeCl₃) and 290.7 grams of 1,1,1,3,3-pentachloropropane.Vacuum and heat were applied until the system began refluxing. Overheadproduct draw was begun using a 0.7/1 reflux ratio. Over the course of292 minutes, the overhead temperature gradually increased from 82 to 103degrees C., while the bottoms rose from 92 to 113 degrees C. Seven timedoverhead samples were collected. The cumulative moles of1,1,3,3-tetrachloropropene recovered and 1,1,1,3,3-pentachloropropanefed at the end of each sample collection period are shown in Table 1 andgraphically represented in FIG. 4. The rate of1,1,3,3-tetrachloropropene formation dropped with time as shown by thedecreasing slope of the 1,1,3,3-tetrachloropropene line.

TABLE 1 Example 1 data Cumulative Run Time, min 24 83 127 177 212 254292 Overhead Sample Duration, min 24 59 44 50 35 42 38 Overhead Temp, C.82 84 90 89 100 100 103 Bottoms Temp, C. 92 100 108 111 110 113 113Absolute Pressure, mm Hg 98 98 98 98 98 98 98 Overhead Sample, grams 51147 92 105 83 111 65 Cumulative grams 291 485 705 929 929 929 1059HCC-240fa Charged Incremental grams 0.26 0 0 0 0 0 0 FeCl3 ChargedCumulative moles 1.34 2.24 3.26 4.29 4.29 4.29 4.89 HCC-240fa ChargedOverhead Sample Comp, wt % HCC-1230za 99.2 99.1 91.7 69.2 43.1 38.8 33.7HCC-240fa 0.8 0.9 8.2 30.6 56.6 61.1 66.3 Overhead moles HCC-1230za0.282 0.807 0.469 0.406 0.198 0.239 0.122 HCC-240fa 0.002 0.006 0.0350.149 0.216 0.313 0.199 Cumulative HCC-1230za 0.282 1.090 1.558 1.9642.162 2.401 2.523

Example 2—Chlorine Addition

Example 2 was conducted in the same manner as Example 1, except that0.21 mole/hr chlorine gas was continuously sparged into the liquid inthe bottoms flask. Over 370 minutes, the overhead temperature remainedessentially constant between 80 and 85 degrees C. The bottomstemperature rose from 92 to about 100 degrees C. within the first 60minutes, then stayed there for the duration. Cumulative moles of1,1,3,3-tetrachloropropene and 1,1,1,3,3-pentachloropropane are alsoshown in FIG. 4 as a comparison to Example 1. The rate of1,1,3,3-tetrachloropropene formation stayed essentially constant. Therate after 150 minutes was higher than in Example 1, even though1,1,1,3,3-pentachloropropane was introduced at a similar rate.

TABLE 2 Example 2 data Cumulative Run Time, min 30 85 121 182 220 286329 370 Overhead Sample Duration, 30 55 36 61 38 66 43 41 min OverheadTemp, C. 85 81 81 83 82 82 80 83 Bottoms Temp, C. 92 98 99 100 101 102101 101 Absolute Pressure, mm Hg 98 100 98 100 100 100 98 98 OverheadSample grams 68 127 80 142 82 140 77 139 Cumulative grams 291 502 605746 857 1034 1221 1221 HCC-240fa Charged Incremental grams FeCl3 0.27 00 0 0 0 0 0 Charged Cumulative moles 1.34 2.32 2.80 3.45 3.96 4.78 5.645.64 HCC-240fa Charged Overhead Sample Comp, wt % HCC-1230za 98.8 97.097.7 96.5 96.9 93.5 93.9 93.0 HCC-240fa 1.2 3.0 2.3 3.5 3.0 6.5 5.8 6.9Overhead moles HCC-1230za 0.371 0.687 0.433 0.764 0.442 0.727 0.400 0.00HCC-240fa 0.004 0.017 0.009 0.023 0.012 0.042 0.021 0.00 CumulativeHCC-1230za 0.371 1.058 1.491 2.255 2.697 3.424 3.824 3.824

Example 3—No Chlorine Addition, Periodic FeCl₃ Addition

This example was conducted similarly to Example 1, except that 0.25 gramof anhydrous FeCl₃ was introduced along with each mole of1,1,1,3,3-pentachloropropane added to the bottoms flask. No chlorine wasfed. Thus, 459.6 grams of 1,1,1,3,3-pentachloropropane and 0.53 grams ofFeCl₃ were charged to the flask initially. The mixture was boiled and1,1,3,3-tetrachloropropene product was removed from the column overheadas before. The first overhead sample, 160.4 grams, was collected for 63minutes. A mixture of 0.26 grams of FeCl₃ in 222.7 grams of1,1,1,3,3-pentachloropropane was slowly added to the bottoms flask asthe next overhead sample was collected. Similar additions were conductedfor the next three overhead samples. Over 402 minutes, overheadtemperatures remained constant between 83 and 85 degrees C. Bottomstemperature slowly rose from 92 to 98 degrees. Cumulative moles of1,1,3,3-tetrachloropropene and 1,1,1,3,3-pentachloropropane are shown inTable 3 and in FIG. 5. Again, the rate of 1,1,3,3-tetrachloropropeneformation remained much higher with time than in Example 1 with only theinitial charge of FeCl₃.

TABLE 3 Example 3 data Cumulative Run Time, min 63 117 207 277 337 402Overhead Sample Duration, min 63 54 90 70 60 65 Overhead Temp, C. 84 8385 84 83 85 Bottoms Temp, C. 92 93 95 96 97 98 Absolute Pressure, mm Hg103 100 98 100 98 98 Overhead Sample grams 160 163 270 187 152 192Cumulative grams HCC-240fa Charged 460 682 1164 1396 1633 1633Incremental grams FeCl3 Charged 0.53 0.26 0.63 0.29 0.32 0 Cumulativemoles HCC-240fa Charged 2.12 3.15 5.38 6.46 7.55 7.55 Overhead SampleComp, wt % HCC-1230za 100 99.9 99.9 99.7 99.6 99.9 HCC-240fa 0.1 0.1 0.10.3 0.4 0.1 Overhead moles HCC-1230za 0.891 0.904 1.496 1.033 0.8431.067 HCC-240fa 0.000 0.001 0.001 0.003 0.003 0.001 CumulativeHCC-1230za 0.891 1.796 3.292 4.326 5.168 6.235

Example 4—Chlorine Addition, No FeCl₃ Present

The catalytic effect of chlorine alone was tested in Example 4. Thus,373 grams of 1,1,1,3,3-pentachloropropane with no FeCl₃ were charged tothe flask. The mixture was boiled and overhead product removed asbefore. Three overhead samples were collected over an 85 minute totalrun time. One addition of 1,1,1,3,3-pentachloropropane was made afterthe second overhead sample. Only 0.03 moles of1,1,3,3-tetrachloropropene were formed after 85 minutes, compared to 1-2moles at similar times in examples 1-3, indicating the catalytic effectof FeCl₃.

TABLE 4 Example 4 data Cumulative Run Time, min 25 55 85 Overhead SampleDuration, min 25 30 30 Overhead Temp, C. 116 114 115 Bottoms Temp, C.120 119 119 Absolute Pressure, mmHg 108 103 103 Overhead Sample grams 3560 47 Cumulative grams HCC-240fa Charged 373 373 455 Incremental gramsFeCl3 Charged 0 0 0 Cumulative moles HCC-240fa Charged 1.72 1.72 2.10Overhead Sample Comp, wt % HCC-1230za 14.4 0.5 0.2 HCC-240fa 85.6 99.599.8 Overhead moles HCC-1230za 0.028 0.002 0.000 HCC-240fa 0.139 0.2740.217 Cumulative HCC-1230za 0.028 0.030 0.030

Various modifications and alterations that do not depart from the scopeand spirit of this invention will become apparent to those skilled inthe art. This invention is not to be duly limited to the illustrativeembodiments set forth herein.

What is claimed is:
 1. A process for the manufacture of1,1,3,3-tetrachloropropene, the process comprising: dehydrochlorinating1,1,1,3,3-pentachloropropane, where said step of dehydrochlorinating1,1,1,3,3-pentachloropropane takes place in the presence of an oxidizingagent and a Lewis acid.
 2. The process of claim 1, where the Lewis acidis ferric chloride.
 3. The process of claim 2, where the oxidizing agentis chlorine.
 4. The process of claim 3, where said step ofdehydrochlorinating takes place in the presence of from about 30 toabout 10,000 ppm ferric chloride.
 5. The process of claim 4, where saidstep of dehydrochlorinating takes place in the presence of from about100 ppm to about 3 wt % chlorine.
 6. The process of claim 5, where saidstep of dehydrochlorinating includes reactive distillation.
 7. Theprocess of claim 1, where said step of dehydrochlorinating takes placeat a pressure of from about 0.05 atmospheres to about 0.5 atmospheres.8. The process of claim 1, where said step of dehydrochlorinatingincludes reactively distilling a crude 1,1,1,3,3-pentachloropropanestream.
 9. The process of claim 8, where the crude1,1,1,3,3-pentachloropropane stream includes1,1,1,3,3-pentachloropropane, carbon tetrachloride, vinyl chloride,iron, and at least one of amines, nitriles, amides, and phosphates. 10.The process of claim 1, where said step of dehydrochlorinating includesreactively distilling a partially purified 1,1,1,3,3-pentachloropropanestream.
 11. The process of claim 10, where said partially purified1,1,1,3,3-pentachloropropane stream includes1,1,1,3,3-pentachloropropane, carbon tetrachloride, and vinyl chloride.12. A process for the manufacture of 1,1,3,3-tetrachloropropene, theprocess comprising: reacting carbon tetrachloride and vinyl chloride inthe presence of a catalyst mixture including organophosphate solvent,iron metal, and ferric chloride under conditions sufficient to produce1,1,1,3,3-pentachloropropane in a reaction stream, separating thereaction stream into a high-boiling-point-component stream and adistillate fraction, the distillate fraction including the1,1,1,3,3-pentachloropropane, and dehydrochlorinating1,1,1,3,3-pentachloropropane
 13. The process of claim 12, where theorganophosphate solvent is tributylphosphate.
 14. The process of claim12, where said step of separating takes place at a temperature fromabout 70° C. to about 120° C.
 15. The process of claim 12, where saidstep of separating takes place at a pressure of at least 0.020atmospheres.
 16. The process of claim 12, where the distillate fractionfurther includes isomers of 1,1,1,3,3-pentachloropropane, unconvertedvinyl chloride, unconverted carbon tetrachloride, and other lightbyproducts, the method further comprising a second separating step,prior to said step of dehydrochlorinating, to separate the distillatefraction into a first stream containing the 1,1,1,3,3-pentachloropropaneand the isomers of 1,1,1,3,3-pentachloropropane and a second streamcontaining the unconverted vinyl chloride, unconverted carbontetrachloride, and other light byproducts.
 17. A process for themanufacture of 1,1,3,3-tetrachloropropene, the process comprising:dehydrochlorinating 1,1,1,3,3-pentachloropropane within a reactionvessel, and periodically adding a Lewis acid to the reaction vesselduring said step of dehydrochlorinating.
 18. The process of claim 17,where the Lewis acid is ferric chloride.
 19. The process of claim 17,where the reaction vessel has a liquid inventory within the reactionvessel and a liquid flow rate out of the reaction vessel, where saidstep of periodically adding the Lewis acid occurs once every 0.5 to 3liquid turnovers, where one liquid turnover is defined as the timecalculated as the ratio of the liquid inventory within the reactionvessel to the liquid flow rate out of the reaction vessel.
 20. Theprocess of claim 17, further comprising a step of adding the Lewis acidto the reaction vessel prior to said step of dehydrochlorinating.